ZMenu near-miss code failed for very zoomed-in images.
ZMenu near-miss code failed for very zoomed-in images.

#331911 (subbugs 2 & 3).

Ensembl/ensembl-webcode,Ensembl/ensembl-webcode,Ensembl/ensembl-webcode,Ensembl/ensembl-webcode,Ensembl/ensembl-webcode